Vincenzo Nibali staged a remarkable comeback to all but secure his second Giro d'Italia title, overcoming a 44-second deficit to overhaul overnight leader Esteban Chaves in a dramatic final stage.

The Italian had been almost five minutes off the lead ahead of Friday's stage, but produced an inspired performance to win the 19th leg and roar back into contention.

And on Saturday's gruelling 134km ride between Guillestre and Sant' Anna Di Vinadro, featuring three category one climbs and a summit finish, the Astana rider successfully reeled his Orica-GreenEDGE rival in, much to the delight of the home fans.

Rein Taaramae became the first Estonian to win a stage at the Giro d'Italia, beating Colombian Darwin Atapuma (BMC Racing) to the line by 52 seconds, but all eyes were on Nibali, who finished sixth to claim the pink jersey.

The 2013 champion came in more than a minute clear of Chaves as the Colombian endured a day to forget in the mountains, with Nibali's attack 15km from the finish proving pivotal.

Chaves could not keep pace with Nibali, who is now poised to win the fourth Grand Tour title of his excellent career.

Steven Kruijswijk (Lotto-Soudal) defied a fractured rib and a foot injury sustained in a crash on Friday to finish 13th in the stage and fourth overall.

Third place in the overall classification went to Spain's Alejandro Valverde (Movistar).

Nibali will be crowned the winner on Sunday as long as he avoids crashing in the final processional stage, with large crowds expected to greet the riders as they descend into Turin.